The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Many enterprises and their computer systems utilize resources that are hosted by a virtual data center and are accessible through the internet, such as cloud storage, cloud computing, or cloud databases. In this arrangement, the enterprise is a client of a virtual data center (VDC). Such virtual data centers may provide a client with many benefits, including reduced costs, easier scalability, and a reduced administrative burden. However, a drawback of utilizing such VDC resources is that the performance qualities of the resources can change over time. For example, there may be significant variation in the time needed to complete a read operation or a write operation. The variance in quality can impact the operation of various client applications that rely on the resources of the virtual data center. Approaches for cost-effectively obtaining consistent performance from cloud storage units are needed.
Additionally, client needs for performance quality may also change over time. For example, the VDC may quantify the performance of its storage units according to redundant array of independent disks (RAID) levels and may establish a first level of RAID configuration or performance, or other data storage policies, for particular data storage units that are assigned to the client, but over time the client may determine that it needs different levels of RAID configuration or performance, or other data storage policies, to fulfill its needs. Adjustment of these policies is typically complicated, requires manual communication between the client and the VDC, and may be disruptive to data storage operations. One approach for meeting service level objectives is to overprovision the resources needed. However, these approaches require high levels of intellectual and capital investment. Approaches for accommodating the changing needs of the client while minimizing costs to the client are needed.